The hydrochemistry of alpine lakes reflects water characteristic and its response to climatic change. Over 300 water samples had been collected from 52 sites of 5 lakes and 7 inflowing rivers in the Yamzhog Yumco Basi...The hydrochemistry of alpine lakes reflects water characteristic and its response to climatic change. Over 300 water samples had been collected from 52 sites of 5 lakes and 7 inflowing rivers in the Yamzhog Yumco Basin, South Tibet, during 2009-2014, basing which the hydrochemical regime and its mechanism were analyzed along with the adoption of hydrological investigations in 1979 and 1984 as well. Results revealed that the waters were hard with weak alkalinity for the Yamzhog Yumco Basin. Most of them were fresh, and the rest were slightly saline. The hydrochemical types of 5 lakes （i.e., Lake Yamzhog Yum Co, Puma Yum Co, Bajiu Co, Kongmu Co, and Chert Co） were SO4^2--HCO3^--Mg^2＋-Na^＋, HCO3^-- SO4^2--Mg^2＋-Ca^2＋, SO4^2--Mg^2＋-Na^＋, SO4^2--HCO3^--Ca^2＋, and SO4^2--Na^＋-Mg^2＋-Ca^2＋, respectively. As for rivers, HCO3^- and SO4^2- were the major anions, and Ca2. was the dominant cation. Lake Yamzhog Yum Co, the largest lake in the basin, exhibited remarkable spatial variations in hydrochemistry at its surface but irregular changes with depth. The weathering of evaporates and carbonates, together with evaporation and crystallization, were the major mechanisms controlling the hydrochemistry of waters in the Yamzhog Yumco Basin. Global warming also had significant impacts on hydrochemical variations.展开更多
AIM:To compare the eradication rates for Helicobacter pylori(H.pylori) and ulcer recurrence of standard triple therapy(STT) and levofloxacin based therapy(LBT).METHODS:Seventy-four patients with perforated duodenal ul...AIM:To compare the eradication rates for Helicobacter pylori(H.pylori) and ulcer recurrence of standard triple therapy(STT) and levofloxacin based therapy(LBT).METHODS:Seventy-four patients with perforated duodenal ulcer treated with simple closure and found to be H.pylori infected on 3 mo follow up were randomized to receive either the STT group comprising of amoxicillin 1 g bid,clarithromycin 500 mg bid and omeprazole 20 mg bid or the LBT group comprising of amoxicillin 1 g bid,levofloxacin 500 mg bid and omeprazole 20 mg bid for 10 d each.The H.pylori eradication rates,side effects,compliance and the recurrence of ulcer were assessed in the two groups at 3 mo follow up.RESULTS:Thirty-four patients in the STT group and 32 patients in the levofloxacin group presented at 3 mo follow up.H.pylori eradication rates were similar with STT and the LBT groups on intention-to-treat(ITT) analysis(69% vs 80%,P = 0.425) and(79% vs 87%,P = 0.513) by per-protocol(PP) analysis respectively.Ulcer recurrence in the STT and LBT groups on ITT analysis was(20% vs 14%,P = 0.551) and(9% vs 6%,P = 1.00) by PP analysis.Compliance and side effects were also comparable between the groups.A complete course of STT costs Indian Rupees(INR) 1060.00,while LBT costs only INR 360.00.CONCLUSION:H.pylori eradication rates and the rate of ulcer recurrence were similar between the STT and LBT.The LBT is a more economical option compared to STT.展开更多
The Huai River Basin is a unique area in P.R.China with the highest densities of population and water projects.It is also subject to the most serious water pollution.We proposed a distributional SWAT(Soil and Water As...The Huai River Basin is a unique area in P.R.China with the highest densities of population and water projects.It is also subject to the most serious water pollution.We proposed a distributional SWAT(Soil and Water Assessment Tool) model coupled with a water quality-quantity balance model to evaluate dam impacts on river flow regimes and water quality in the middle and upper reaches of the Huai River Basin.We calibrated and validated the SWAT model with data from 29 selected cross-sections in four typical years(1971,1981,1991 and 1999) and used scenario analysis to compensate for the unavailability of historical data regarding uninterrupted river flows before dam and floodgate construction,a problem of prediction for ungauged basins.The results indicate that dam and floodgate operations tended to reduce runoff,decrease peak value and shift peaking time.The contribution of water projects to river water quality deterioration in the concerned river system was between 0 to 40%,while pollutant discharge contributed to 60% to 100% of the water pollution.Pollution control should therefore be the key to the water quality rehabilitation in the Huai River Basin.展开更多
This paper investigates a time-inconsistent stochastic linear-quadratic problem with regime switching that is characterized via a finite-state Markov chain.Open-loop equilibrium control is studied in this paper whose ...This paper investigates a time-inconsistent stochastic linear-quadratic problem with regime switching that is characterized via a finite-state Markov chain.Open-loop equilibrium control is studied in this paper whose existence is characterized via Markov-chain-modulated forward-backward stochastic difference equations and generalized Riccati-like equations with jumps.展开更多
基金National Natural Science Foundation of China, No.41471064, No.41171062
文摘The hydrochemistry of alpine lakes reflects water characteristic and its response to climatic change. Over 300 water samples had been collected from 52 sites of 5 lakes and 7 inflowing rivers in the Yamzhog Yumco Basin, South Tibet, during 2009-2014, basing which the hydrochemical regime and its mechanism were analyzed along with the adoption of hydrological investigations in 1979 and 1984 as well. Results revealed that the waters were hard with weak alkalinity for the Yamzhog Yumco Basin. Most of them were fresh, and the rest were slightly saline. The hydrochemical types of 5 lakes （i.e., Lake Yamzhog Yum Co, Puma Yum Co, Bajiu Co, Kongmu Co, and Chert Co） were SO4^2--HCO3^--Mg^2＋-Na^＋, HCO3^-- SO4^2--Mg^2＋-Ca^2＋, SO4^2--Mg^2＋-Na^＋, SO4^2--HCO3^--Ca^2＋, and SO4^2--Na^＋-Mg^2＋-Ca^2＋, respectively. As for rivers, HCO3^- and SO4^2- were the major anions, and Ca2. was the dominant cation. Lake Yamzhog Yum Co, the largest lake in the basin, exhibited remarkable spatial variations in hydrochemistry at its surface but irregular changes with depth. The weathering of evaporates and carbonates, together with evaporation and crystallization, were the major mechanisms controlling the hydrochemistry of waters in the Yamzhog Yumco Basin. Global warming also had significant impacts on hydrochemical variations.
文摘AIM:To compare the eradication rates for Helicobacter pylori(H.pylori) and ulcer recurrence of standard triple therapy(STT) and levofloxacin based therapy(LBT).METHODS:Seventy-four patients with perforated duodenal ulcer treated with simple closure and found to be H.pylori infected on 3 mo follow up were randomized to receive either the STT group comprising of amoxicillin 1 g bid,clarithromycin 500 mg bid and omeprazole 20 mg bid or the LBT group comprising of amoxicillin 1 g bid,levofloxacin 500 mg bid and omeprazole 20 mg bid for 10 d each.The H.pylori eradication rates,side effects,compliance and the recurrence of ulcer were assessed in the two groups at 3 mo follow up.RESULTS:Thirty-four patients in the STT group and 32 patients in the levofloxacin group presented at 3 mo follow up.H.pylori eradication rates were similar with STT and the LBT groups on intention-to-treat(ITT) analysis(69% vs 80%,P = 0.425) and(79% vs 87%,P = 0.513) by per-protocol(PP) analysis respectively.Ulcer recurrence in the STT and LBT groups on ITT analysis was(20% vs 14%,P = 0.551) and(9% vs 6%,P = 1.00) by PP analysis.Compliance and side effects were also comparable between the groups.A complete course of STT costs Indian Rupees(INR) 1060.00,while LBT costs only INR 360.00.CONCLUSION:H.pylori eradication rates and the rate of ulcer recurrence were similar between the STT and LBT.The LBT is a more economical option compared to STT.
基金Funded by the Key Project of International Cooperation of the Natural Science Foundation of China (No. 40721140020)the Key Project of the Natural Science Foundation of China (No. 40730632)
文摘The Huai River Basin is a unique area in P.R.China with the highest densities of population and water projects.It is also subject to the most serious water pollution.We proposed a distributional SWAT(Soil and Water Assessment Tool) model coupled with a water quality-quantity balance model to evaluate dam impacts on river flow regimes and water quality in the middle and upper reaches of the Huai River Basin.We calibrated and validated the SWAT model with data from 29 selected cross-sections in four typical years(1971,1981,1991 and 1999) and used scenario analysis to compensate for the unavailability of historical data regarding uninterrupted river flows before dam and floodgate construction,a problem of prediction for ungauged basins.The results indicate that dam and floodgate operations tended to reduce runoff,decrease peak value and shift peaking time.The contribution of water projects to river water quality deterioration in the concerned river system was between 0 to 40%,while pollutant discharge contributed to 60% to 100% of the water pollution.Pollution control should therefore be the key to the water quality rehabilitation in the Huai River Basin.
基金the National Key R&D Program of China under Grant No.2018YFA0703800the National Natural Science Foundation of China under Grant Nos.61773222,61877057 and 61973172。
文摘This paper investigates a time-inconsistent stochastic linear-quadratic problem with regime switching that is characterized via a finite-state Markov chain.Open-loop equilibrium control is studied in this paper whose existence is characterized via Markov-chain-modulated forward-backward stochastic difference equations and generalized Riccati-like equations with jumps.
